Co-owned U.S. Pat. No. 5,073,170 discloses a retention device having an adhesive pad and a tube retainer secured to the pad's upper surface. A flexible strap extends from one side of the retainer and may be looped about a drainage tube so that when the strap's free end is inserted through a passage in the retainer body containing a detent or latch mechanism, the strap may be drawn tightly about the tube to immobilize the same. The Y-shaped configuration of the strap with its diverging arms secured to the retainer on opposite sides of the entrance opening to the passage permits the strap to be drawn tightly about even the smallest drainage tubes or catheters in common use.
While the patented device is highly effective in securing immobilizing drainage tubes over a wide range of sizes, the procedure for releasing the latching mechanism may not be immediately apparent to an attendant unfamiliar with the device. Such release involves lifting an exposed extension or handle of the latching member located within the passage. The lifting action may be awkward to perform and, even if done properly, may result in the transmission of pulling forces to the skin areas surrounding the exit site. Pulling or lifting forces applied to that site may cause considerable patient discomfort. To reduce such discomfort, the attendant may use the fingers of his/her other hand to restrain movement of the adhesive pad as the latching member is raised. While such a measure may avoid or reduce discomfort, it requires the use of both hands, leaving no hand free for the attendant to retract the strap from the passage when the latching member has been so raised.
In addition, it has now been found that while the patented device operates with a wide range of tube sizes and is especially effective in retaining drainage tubes of the smaller sizes (which prior retention devices often failed in securely restraining), the forces required to draw the strap tightly about larger-sized tubes tends to be greater than for smaller tubes because of the sharper directional change of the strap as it enters the retainer body. Again, the need for applying added force not only presents operational problems but would be expected to add to patient discomfort.
Accordingly, it is a main aspect of this invention to provide an improved tube retention device which is easily operated with tubes over the full range of sizes and which minimizes if not eliminates patient discomfort when the device is operated to secure or release a drainage tube. Problems of patient discomfort caused by the transmission of pushing or pulling forces towards or away from the skin surface are eliminated, or at least greatly reduced, because the forces required to operate the device are balanced and are not exerted in directions perpendicular to that surface. To release the latch mechanism, a user simply squeezes a pair of side flanges of the tube retainer with such opposing and offsetting forces being applied in directions parallel with the patient's skin.
Briefly, the device takes the form of a flexible pad having upper and lower surfaces and with a pressure-sensitive adhesive layer along its lower surface for adherence to a patient's skin. A tube retainer is mounted upon the pad's upper surface and includes a retainer body having a passage extending therethrough. An elongated strap has one end portion joined to the body adjacent the entrance to the passage and an opposite free end portion insertable into and through the passage. When so inserted, the strap forms a loop for receiving and holding a drainage tube.
In a preferred embodiment, the retainer body includes a pair of side walls extending along the passage, the side walls being pivotally connected along their upper edges to a pair of lever arms or side flanges. Such lever arms have relatively rigid lower portions extending downardly below the upper edges of the side walls and spaced laterally from those side walls. The arms also have upper portions projecting above the edges, and a flexible top wall joins such upper portions. The top wall includes a central portion that normally curves downwardly into the passage but is forced into a partially straightened or raised condition when the rigid lower portions of the lever arms are pivoted towards each other. A pawl or latch member extends downwardly from the central portion of the top wall for engaging the ratchet teeth of the strap and preventing reverse movement of the strap in the passage unless and until the depending portions of the lever arms are squeezed towards each other between the operator's fingers.
The device may have its strap oriented so that the axis of the loop (or the plane of the strap) extends either horizontally or vertically. In an embodiment in which the orientation is horizontal, the strap is joined to the retainer body well above the plane of the pad, at approximately the level of the imperforate guide wall that defines the bottom surface of the passage through the retainer body. Ideally, that surface lies along a plane that substantially bisects the loop formed by the strap when the strap is tightened about a drainage tube. Approximately equal portions of the loop are thereby disposed above and below that plane to reduce the sharpness of curvature of the strap that would otherwise develop at the entrance to the passage if such portions were unequal in size.
A similar result occurs in an embodiment in which the strap is vertically oriented. In such a construction, however, the pawl has a laterally-directed and preferably angular latching surface and, in addition, the strap may have camming shoulder for directing the flexible latching member laterally out of engagement with the ratchet teeth of the strap when that member is raised by squeezing forces applied to the depending lever arms or flanges.
Other features, advantages, and objects of the invention will become apparent from the specification and drawings.